Inelastic low-temperature transport through a quantum dot with a Mn ion

Kondo peak splitting and Kondo dip induced by a local moment

“…The non-equilibrium Green’s function method has been widely used in the discussion of Kondo effects in quantum dots 5 47 –5 1 . In order to handle the large spin involved in many problems, we use the Hubbard operator Green’s function method 34 , which has been used to solve the transport problems in the linear response, non-linear response, and Kondo regimes 52 53 54 . In this Hubbard operator representation, the electron operators in the dot are rewritten as with δ σ = +1(−1) for σ = ↑(↓), , s + = X ↑↓ and s − = X ↓↑ .…”

Multi-step shot noise spectrum induced by a local large spin

“…The non-equilibrium Green's function (GF) approach in the language of molecular states, i.e., the language of Hubbard operators is used in this paper. [34][35][36][37][38][39][40][41] This method absorbs the advantage of quantum master equations, which use manybody states as the basis in the reduced density matrix. [42] In this Hubbard operator representation, the electron operators in the dot are rewritten as…”

“…In one-electron regime (U → ∞) the double-occupation is forbidden and c σ = X 0σ . The large spin operators can be expressed as [34][35][36]…”

“…For technical details, one can refer to our previous papers. [34][35][36] Once the single-particle Green's function is obtained, the occupation, current, shot noise, and Fano factor can be calculated along the lines of Refs. [46] and [47].…”

“…To deal with the local large spin, we use the language of molecular states, i.e., the Hubbard operators. [34][35][36] In the linear response regime, the shot noise shows 2S + 1 peaks and is strongly spin-dependent. In the nonlinear response regime, one can observe 2S + 1 steps in shot noise spectrum and Fano factor.…”